This invention relates to equipment for monitoring and selectively distributing incoming telephone calls to a plurality of telephones, and more particularly to means for providing an audible indication of the quantity of unanswered incoming calls that are awaiting service.
It is quite common to use special call distributing equipment for storing and selectively connecting incoming telephone calls to a plurality of phones connected to a single line. With this equipment, as the number or incoming calls increases beyond the available telephones, the calls are placed on "hold", and are connected to a telephone as soon as one becomes available. Moreover, some such equipment has been supplemented with a so-called flash interpreter device for indicating visually the number of incoming calls which are awaiting service.
With one such flash interpreter device the number of calls awaiting service are converted to pulsating electrical signals, which increase in frequency in correspondence with the increase in the number of incoming telephone calls which are on "hold". These pulsating signals are then used selectively to illuminate a series (e.g. three) differently colored warning lights, one of which is illuminated when the call backup signal is at a relatively low frequency, another of which is illuminated when the frequency of the call backup signal increases to another, higher range, and a third one of which is illuminated when the signal increases to still a third frequency range higher than both the first and second ranges. In this manner the person or persons supervising the telephone operation can readily perceive the relative quantity of incoming calls that are backed up at any instant.
One of the disadvantages of this type of device is that, when the supervisor of the telephone operators becomes very busy, he or she has a tendency to overlook the warning lamps, and therefore does not take any available action to minimize the backup of calls, particularly if the warning lamps are placed overhead or near one end of the room containing the phones.
It is an object of this invention, therefore, to provide means for improving telephone monitoring equipment of the type described. To this end it is an object also to provide for such equipment audible alarm means which operates intermittently to inform supervisory personnel, or the like, that incoming telephone calls have reached, or fallen below, predetermined levels.
Still a more specific object of this invention is to provide a novel phone call backup interpreter mechanism which produces an audible chime tone upon predetermined changes in calls awaiting service.
Other objects of the invention will be apparent hereinafter from the specification and from the recital of the appended claims, particularly when read in conjunction with the accompanying drawing.